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1.
Phys Rev Lett ; 127(8): 086802, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477427

RESUMO

We report the preparation and readout of multielectron high-spin states, a three-electron quartet, and a four-electron quintet, in a gate-defined GaAs/AlGaAs single quantum dot using spin filtering by quantum Hall edge states coupled to the dot. The readout scheme consists of mapping from multielectron to two-electron spin states and a subsequent two-electron spin readout, thus obviating the need to resolve dense multielectron energy levels. Using this technique, we measure the relaxations of the high-spin states and find them to be an order of magnitude faster than those of low-spin states. Numerical calculations of spin relaxation rates using the exact diagonalization method agree with the experiment. The technique developed here offers a new tool for the study and application of high-spin states in quantum dots.

2.
Phys Rev Lett ; 117(23): 236802, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982642

RESUMO

We report on the single-shot readout of three two-electron spin states-a singlet and two triplet substates-whose z components of spin angular momentum are 0 and +1, in a gate-defined GaAs single quantum dot. The three spin states are distinguished by detecting spin-dependent tunnel rates that arise from two mechanisms: spin filtering by spin-resolved edge states and spin-orbital correlation with orbital-dependent tunneling. The three states form one ground state and two excited states, and we observe the spin relaxation dynamics among the three spin states.

3.
Neuroscience ; 313: 10-22, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26601776

RESUMO

In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Gânglios Espinais/metabolismo , Lisossomos/metabolismo , Neurônios/metabolismo , Nervos Espinhais/lesões , Trifosfato de Adenosina/metabolismo , Adenoviridae/genética , Animais , Modelos Animais de Doenças , Exocitose/fisiologia , Gânglios Espinais/patologia , Vetores Genéticos , Glicoproteínas/metabolismo , Lectinas/metabolismo , Vértebras Lombares , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Proteínas de Membrana Lisossomal/genética , Proteínas de Membrana Lisossomal/metabolismo , Masculino , Microglia/metabolismo , Neurônios/patologia , Proteínas de Transporte de Nucleotídeos/genética , Proteínas de Transporte de Nucleotídeos/metabolismo , RNA Mensageiro/metabolismo , Ratos Wistar , Nervos Espinhais/metabolismo , Versicanas , Proteína Vermelha Fluorescente
4.
Cell Death Dis ; 5: e1007, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24434515

RESUMO

Abnormal reflexes associated with spasticity are considered a major determinant of motor impairments occurring after stroke; however, the mechanisms underlying post-stroke spasticity remain unclear. This may be because of the lack of suitable rodent models for studying spasticity after cortical injuries. Thus, the purpose of the present study was to establish an appropriate post-stroke spasticity mouse model. We induced photothrombotic injury in the rostral and caudal forelimb motor areas of mice and used the rate-dependent depression (RDD) of Hoffmann's reflex (H-reflex) as an indicator of spastic symptoms. To detect motoneuron excitability, we examined c-fos mRNA levels and c-Fos immunoreactivity in affected motoneurons using quantitative real-time reverse transcription PCR and immunohistochemical analysis, respectively. To confirm the validity of our model, we confirmed the effect of the anti-spasticity drug baclofen on H-reflex RDDs 1 week post stroke. We found that 3 days after stroke, the RDD was significantly weakened in the affected muscles of stroke mice compared with sham-operated mice, and this was observed for 8 weeks. The c-fos mRNA levels in affected motoneurons were significantly increased in stroke mice compared with sham-operated mice. Immunohistochemical analysis revealed a significant increase in the number of c-Fos-positive motoneurons in stroke mice compared with sham-operated mice at 1, 2, 4, and 8 weeks after stroke; however, the number of c-Fos-positive motoneurons on both sides of the brain gradually decreased over time. Baclofen treatment resulted in recovery of the weakened RDD at 1 week post stroke. Our findings suggest that this is a viable animal model of post-stroke spasticity.


Assuntos
Infarto Cerebral/complicações , Neurônios Motores/fisiologia , Debilidade Muscular/fisiopatologia , Reflexo Anormal , Animais , Baclofeno/administração & dosagem , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios Motores/química , Neurônios Motores/efeitos dos fármacos , Debilidade Muscular/tratamento farmacológico , Debilidade Muscular/etiologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo
5.
Neuroscience ; 256: 426-32, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24184980

RESUMO

MicroRNA (miRNA) is a small non-coding RNA that regulates gene expression by degrading target mRNAs or inhibiting translation. Although many miRNAs play important roles in various conditions, it is unclear whether miRNAs are involved in motor nerve regeneration. In this study, we identified the possible implication of miR-124 in nerve regeneration using a mouse hypoglossal nerve injury model. The significant down-regulation of miR-124 was observed in injured hypoglossal motor neurons after nerve injury, and this transient down-regulation showed a clear inverse correlation with the up-regulation of KLF6 and STAT3, known as axon elongation factor and regeneration-associated molecules, respectively. Furthermore, the luciferase assay and in vitro gain of function methods supported that both genes could be potent targets of miR-124. These results suggest that injury-induced repression of miR-124 may be implicated in the regulation of expression of several injury-associated transcription factors, which are crucial for appropriate nerve regeneration.


Assuntos
Regulação para Baixo/fisiologia , Traumatismos do Nervo Hipoglosso/patologia , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/metabolismo , Neurônios Motores/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT3/genética , Animais , Axotomia , Modelos Animais de Doenças , Regulação para Baixo/genética , Regulação da Expressão Gênica , Células HeLa , Humanos , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas/metabolismo , Fator de Transcrição STAT3/metabolismo , Transfecção
6.
Phys Rev Lett ; 110(26): 266803, 2013 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-23848908

RESUMO

We demonstrate one and two photoelectron trapping and the subsequent dynamics associated with interdot transfer in double quantum dots over a time scale much shorter than the typical spin lifetime. Identification of photoelectron trapping is achieved via resonant interdot tunneling of the photoelectrons in the excited states. The interdot transfer enables detection of single photoelectrons in a nondestructive manner. When two photoelectrons are trapped at almost the same time we observed that the interdot resonant tunneling is strongly affected by the Coulomb interaction between the electrons. Finally the influence of the two-electron singlet-triplet state hybridization has been detected using the interdot tunneling of a photoelectron.

7.
J Neuroendocrinol ; 24(10): 1335-45, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22612533

RESUMO

The integrity of homeostasis can be affected by chronic stress, and hyposomatotropism is evident in chronic stress-associated illnesses. In the present study, we demonstrated that a continuous stress (CS) severely affected somatotrophs among hormone-secreting cells in the anterior lobe (AL) of the pituitary by using a rat CS model. Among AL cells, the proliferation of somatotrophs was almost entirely suppressed in rats that had 3-5 days of CS (5dCS), although other hormone-secreting cells continued to proliferate. The cell size of somatotrophs was reduced at 5dCS (P<0.01), the number of secretory granules was increased at 3dCS (P<0.01) and serum growth hormone (GH) was on declining trend during 1 to 5dCS, suggesting that GH release was inhibited. GH-releasing hormone (GHRH) mRNA level in the arcuate nucleus was transiently decreased, whereas its receptor expression in the AL was significantly increased in CS rats. When 5dCS rats were injected with GHRH, transient GH secretion was observed, whereas proliferation of somatotrophs did not occur. The GHRH administration failed to stimulate extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and the nuclear translocation of ERK in somatotrophs. These results suggest that somatotrophs of 5dCS rats expressed sufficient GHRH receptor, which could transfer a signal for GH release. However, the GHRH-induced proliferation signal was blocked somewhere between the receptor and ERK1/2. Because significant increase of corticosterone in the initial stage (the 1-3dCS) was observed in this model, the corticosterone may affect the signalling. Although the mechanism underlying the blockage of the proliferation signal in somatotrophs under CS remains unclear, these somatotrophic disorder, suggesting that the present animal model may be useful for understanding the molecular mechanisms of chronic stress-associated illnesses.


Assuntos
Proteína Quinase 1 Ativada por Mitógeno/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/fisiologia , Somatotrofos/fisiologia , Estresse Psicológico/metabolismo , Animais , Western Blotting , Proliferação de Células , Doença Crônica , Corticosterona/metabolismo , Ativação Enzimática/fisiologia , Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação , Adeno-Hipófise/fisiologia , Adeno-Hipófise/ultraestrutura , Transporte Proteico/fisiologia , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Somatotrofos/ultraestrutura
8.
Phys Rev Lett ; 106(14): 146804, 2011 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21561212

RESUMO

We demonstrate single-shot detection of single electrons generated by single photons using an electrically tunable quantum dot and a quantum point contact charge detector. By tuning the quantum dot in a Coulomb blockade before the photoexcitation, we observe the trapping and subsequent resetting of single photogenerated electrons. The photogenerated electrons can be stored in the dot for a tunable time range from shorter to longer than the spin-flip time T1. We combine this trap-reset technique with spin-dependent tunneling under magnetic fields to observe the spin-dependent photon detection within the T1.

9.
Neuroscience ; 175: 273-80, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-21093549

RESUMO

The pancreatitis-associated protein (PAP) family (also known as the regenerating gene (Reg) family) is a group of 16 kDa secretory proteins structurally classified as the calcium dependent-type lectin superfamily. Some PAP family members are expressed in neurons following peripheral nerve injury and traumatic brain injury. To determine whether PAP family members are expressed in non-traumatic brain injury, expressions were analyzed following kainic acid (KA)-induced seizure. PAP-I (also known as Reg2 in rat and RegIII-beta in mouse) and pancreatitis associated protein-III (PAP-III; RegIII-gamma in mouse) messenger ribonucleic acid (mRNA) was transiently expressed in some restricted areas, such as the hippocampus and parahippocampal area; expression was observed immediately at a maximal level 1 day after seizure. Expression disappeared within 3 days after seizure. In situ hybridization (ISH) and immunohistochemistry revealed neuronal PAP-I and PAP-III expression in the hippocampal dentate gyrus, perirhinal and entorhinal cortices, and the posterior cortical nucleus of the amygdala. The number of PAP-III mRNA-positive neurons was significantly greater than PAP-I mRNA-positive neurons. The majority of positive neurons co-localized with c-Jun, but not with glutamic acid decarboxylase (GAD). These results may suggest that PAP-I and PAP-III induction in non-GABAergic neurons would protect neurons against damage following seizure.


Assuntos
Aminopeptidases/biossíntese , Antígenos de Neoplasias/biossíntese , Biomarcadores Tumorais/biossíntese , Epilepsia do Lobo Temporal/metabolismo , Lectinas Tipo C/biossíntese , Convulsões/metabolismo , Lobo Temporal/metabolismo , Aminopeptidases/genética , Aminopeptidases/fisiologia , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/fisiologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/fisiologia , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/prevenção & controle , Ácido Caínico/antagonistas & inibidores , Ácido Caínico/toxicidade , Lectinas Tipo C/genética , Lectinas Tipo C/fisiologia , Masculino , Neurotoxinas/antagonistas & inibidores , Neurotoxinas/toxicidade , Proteínas Associadas a Pancreatite , Ratos , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Lobo Temporal/fisiopatologia , Ácido gama-Aminobutírico/fisiologia
10.
J Neuroendocrinol ; 22(11): 1157-64, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20722976

RESUMO

Meniere's disease, characterised by episodic vertigo, fluctuating hearing loss and tinnitus, can occur under conditions of stress. Its pathology was first revealed to be inner ear hydrops through temporal bone studies in 1938. Although its pathogenesis has been proposed to be a disorder of water transport in the inner ear, subsequently, it remains unsolved, until now. A recent study revealed that both plasma stress hormone, vasopressin (pAVP) and its receptor, V2 (V2R) expression in the inner ear endolymphatic sac were significantly higher in Meniere's patients. In the present study, to link V2R-related molecules and inner ear hydrops, we examined V2R-linked water channel molecule, aquaporin-2 (AQP2) expression and translocation in human endolymphatic sac. AQP2 mRNA expression in the endolymphatic sac was significantly higher in Meniere's patients by using real-time polymerase chain reaction, as further confirmed by western blotting. AQP2-like immunoreactivity (-LIR) was translocated from luminal to basolateral side with endosomal trapping in the endolymphatic sac at the time of AVP exposure in human endolymphatic sac tissue culture. The similar AQP2-LIR translocation was also demonstrated by forskolin and blocked by vasopressin/V2R specific antagonist, OPC31260 and protein kinase A (PKA) specific antagonists, H-89 and KT-5720. We concluded that in the pathogenesis of inner ear hydrops resulting in Meniere's attacks, pAVP elevation as a result of stress and subsequent V2R-cAMP-PKA-AQP2 activation and endosomal trapping of AQP2 in the endolymphatic sac, might be important as a basis of this disease. Further experimental and clinical studies are needed to better clarify the neuroscientific relationship between stress and Meniere's disease.


Assuntos
Aquaporina 2/biossíntese , Saco Endolinfático/metabolismo , Doença de Meniere/genética , Doença de Meniere/metabolismo , Adulto , Antagonistas dos Receptores de Hormônios Antidiuréticos , Aquaporina 2/genética , Western Blotting , DNA/genética , Interpretação Estatística de Dados , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia de Fluorescência , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , RNA/biossíntese , RNA/genética , Receptores de Vasopressinas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa/genética , Translocação Genética
11.
Neuroscience ; 169(4): 1527-34, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20600660

RESUMO

In rats under continuous stress (CS) there is decreased hypothalamic dopaminergic innervation to the intermediate lobe (IL) of the pituitary gland, which causes hyperactivation and subsequent degeneration of melanotrophs in the IL. In this study, we investigated the molecular basis for the changes that occur in melanotrophs during CS. Using microarray analysis, we identified several genes differentially expressed in the IL under CS conditions. Among the genes up-regulated under CS conditions, we focused on the inhibitor of DNA binding/differentiation (Id) family of dominant negative basic helix-loop-helix (bHLH) transcription factors. RT-PCR, Western blotting and in situ hybridization confirmed the significant inductions of Id1, Id2 and Id3 in the IL of CS rats. Administration of the dopamine D2 receptor agonist bromocriptine prevented the inductions of Id1-3 in the IL of CS rats, whereas application of the dopamine D2 antagonist sulpiride induced significant expressions of Id1-3 in the IL of normal rats. Moreover, an in vitro study using primary cultured melanotrophs demonstrated a direct effect on Id1-3 inductions by dopamine suppression. These results suggest that the decreased dopamine levels in the IL during CS induce Id1-3 expressions in melanotrophs. Because Id family members inhibit various bHLH transcription factors, it is conceivable that the induced Id1-3 would cooperatively modulate gene expressions in melanotrophs under CS conditions to induce hormone secretion.


Assuntos
Dopamina/fisiologia , Proteína 1 Inibidora de Diferenciação/genética , Proteína 2 Inibidora de Diferenciação/genética , Proteínas Inibidoras de Diferenciação/genética , Melanotrofos/metabolismo , Hipófise/metabolismo , Estresse Psicológico/metabolismo , Animais , Células Cultivadas , Modelos Animais de Doenças , Masculino , Melanotrofos/efeitos dos fármacos , Hipófise/citologia , Hipófise/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Estresse Psicológico/fisiopatologia
12.
J Neuroendocrinol ; 20(12): 1295-300, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19094077

RESUMO

Meniere's disease is peculiar to humans and is characterised by episodic vertigo, fluctuating hearing loss and tinnitus, and attacks of the affliction occurring under conditions of stress. Its pathology was first revealed to be inner ear hydrops through temporal bone studies in 1938. Although subsequently proposed as a disorder of water metabolism in the inner ear, its pathogenesis remains unsolved. The present study aimed to assess the link between the inner ear pathology in Meniere's disease and vasopressin, an anti-diuretic stress hormone with a potential role in inner ear fluid homeostasis. Blood samples were obtained from Meniere's disease patients in the morning, before any surgical treatment, to examine plasma vasopressin (pAVP) levels, and then from inner ear tissue during surgical treatment, to examine vasopressin type-2 receptor (V2R) in the endolymphatic sac. pAVP and the relative V2R mRNA expression in the endolymphatic sac were examined using a real-time polymerase chain reaction. Relative cAMP activity in the endolymphatic sac was also examined using tissue culture and cAMP assay. Both pAVP (1.6-fold versus controls; P = 0.048) and inner ear V2R mRNA expression (41.5-fold versus controls; P = 0.022) were significantly higher in Meniere's patients. cAMP activity was basally up-regulated (2.1-fold versus controls) and cAMP sensitivity to vasopressin application was largely elevated (4.9-fold versus controls) in Meniere's patients. We conclude that, in the pathogenesis of inner ear hydrops, resulting in Meniere's attacks, elevation of pAVP levels (probably as a result of stress) may present as a matter of consequence, but susceptibility of the V2R-overexpressed and cAMP-hypersensitized inner ear to pAVP elevation might be essential as the basis of this disease. Further experimental and clinical studies are needed to better clarify the relationship between Meniere's disease and stress.


Assuntos
Orelha Interna/fisiopatologia , Doença de Meniere/sangue , Doença de Meniere/fisiopatologia , Receptores de Vasopressinas/metabolismo , Vasopressinas/sangue , Animais , AMP Cíclico/metabolismo , Orelha Interna/metabolismo , Feminino , Humanos , Masculino , Doença de Meniere/cirurgia , Neuroma Acústico/sangue , Neuroma Acústico/patologia , Neuroma Acústico/cirurgia
13.
Ital J Anat Embryol ; 112(3): 157-68, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18078237

RESUMO

The current work has documented the expression of the mRNAs for serine protease inhibitor 3 (SPI-3) in the facial and hypoglossal nuclei following peripheral nerve transection by using the in situ hybridization method. The signals appeared 6 hour after nerve injury; they became stronger on day 1 of injury and persisted for 21 days. SPI-3 may be involved during early events of modulating the activities of serine proteases following nerve injury. Such activities may include synaptic stripping and re-organization and facilitation of glial cell reaction to nerve injury. In the later stages of nerve injury SPI-3 may enhance neuronal survival, growth of neurites and re-establishment of synaptic contacts in the facial and hypoglossal nuclei. Hypoglossal but not facial nerve transection caused the expression of mRNAs for SPI-3 in the pineal gland. The signals appeared 6 hours after nerve injury and persisted for 21 days. The significance of this observation is not known but it indicates that the pineal gland senses injury to some peripheral nerves including the hypoglossal nerve. The study has also showed that axotomy of the sciatic nerve did not give rise to the up-regulation of the mRNAs for SPI-3 in the spinal cord. There was no hybridization signals in the lumbar segments; an indication that SPI-3 may not form part of molecules that are released during sciatic nerve transaction by the neural and non-neural cells of the spinal cord. At the moment there are no antibodies for SPI-3 and therefore future studies are needed to verify the findings. It will be interesting also to study on the role of pineal gland during peripheral nerve injuries.


Assuntos
Proteínas de Fase Aguda/genética , Traumatismos do Nervo Facial/metabolismo , Doenças do Nervo Hipoglosso/metabolismo , Neurônios Motores/metabolismo , Sistema Nervoso Periférico/lesões , RNA Mensageiro/metabolismo , Serpinas/genética , Animais , Nervo Facial/metabolismo , Nervo Facial/patologia , Traumatismos do Nervo Facial/genética , Traumatismos do Nervo Facial/patologia , Cones de Crescimento/metabolismo , Cones de Crescimento/ultraestrutura , Nervo Hipoglosso/metabolismo , Nervo Hipoglosso/patologia , Doenças do Nervo Hipoglosso/genética , Doenças do Nervo Hipoglosso/patologia , Hibridização In Situ , Masculino , Neurônios Motores/patologia , Regeneração Nervosa/genética , Vias Neurais/metabolismo , Vias Neurais/patologia , Nervos Periféricos/imunologia , Nervos Periféricos/patologia , Sistema Nervoso Periférico/metabolismo , Sistema Nervoso Periférico/patologia , Glândula Pineal/metabolismo , Glândula Pineal/patologia , Ratos , Ratos Wistar , Recuperação de Função Fisiológica , Rombencéfalo/metabolismo , Rombencéfalo/patologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Sinapses/metabolismo , Sinapses/ultraestrutura
14.
Neuroscience ; 141(4): 1961-9, 2006 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16784821

RESUMO

Heparan sulfate proteoglycans, which bear long chains of heparan sulfate glycosaminoglycan, play significant roles during embryogenesis, including the formation of the CNS. However, their involvement in nerve regeneration has not yet been clarified. Here, we found that the mRNA expression of EXT2, one of the crucial enzymes for heparan sulfate-glycosaminoglycan synthesis, was markedly up-regulated in injured hypoglossal motor neurons after axotomy. In addition, immunohistochemical staining with an antibody specific for heparan sulfate-glycosaminoglycan chains demonstrated increased expression of heparan sulfate-glycosaminoglycan chains in the injured nucleus. Furthermore, the mRNA expressions of glypican-1 and syndecan-1, which are both well-known heparan sulfate proteoglycans, were prominently up-regulated in injured motor neurons. These results suggest that the biosynthesis of heparan sulfate chains promoted by EXT2 is activated in injured motor neurons, and that glypican-1 and syndecan-1 are potent candidates for heparan sulfate proteoglycans involved in peripheral nerve regeneration.


Assuntos
Regulação da Expressão Gênica/fisiologia , Heparitina Sulfato/metabolismo , Doenças do Nervo Hipoglosso/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Fator 3 Ativador da Transcrição/genética , Fator 3 Ativador da Transcrição/metabolismo , Animais , Axotomia/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica/métodos , Hibridização In Situ/métodos , Camundongos , Camundongos Endogâmicos C57BL , N-Acetilglucosaminiltransferases/genética , Polissacarídeo-Liases/farmacologia , RNA Mensageiro/metabolismo , Fatores de Tempo
15.
Neuroscience ; 141(1): 299-310, 2006 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-16675137

RESUMO

Neuropeptides are crucial mediators in nervous and endocrine systems. Processing and degradation, the major regulatory mechanisms, of enzymes are essential for the control of these peptidergic intercellular signaling systems. Damage-induced neuronal endopeptidase (or endothelin converting enzyme-like1), a member of the neprilysin family, has recently been identified as an M13 zinc metalloprotease. Damage-induced neuronal endopeptidase mRNA expression is strikingly restricted to neurons, and is remarkably induced in response to various types of neuronal injuries, although its function and substrate remain unknown. To clarify the role of damage-induced neuronal endopeptidase, we examined the localization and ontogeny of damage-induced neuronal endopeptidase mRNA expression in the rat nervous system using in situ hybridization. Damage-induced neuronal endopeptidase mRNA was detected at embryonic day 12, and its expression restricted to the ventral region of the neural tube. Subsequently, expression was also apparent in primordia of the striatum, hypothalamus, and cranial motor nuclei during neural development. This specific distribution was relatively maintained in the adult brain, although expression levels became weaker. Expression of damage-induced neuronal endopeptidase was absent in the cerebral cortex, hippocampus, and cerebellum. In addition to prominent expression in CNS, intestinal and sensory ganglia and retina demonstrated transient intense damage-induced neuronal endopeptidase mRNA expression during the embryonic period that then declined, and disappeared after birth. The results indicated that damage-induced neuronal endopeptidase might play an important role in embryonic neural development, in particular in peripheral ganglia derived from the neural crest, and in some neurons originating from the basal plate such as the hypothalamus and cranial motor neurons.


Assuntos
Expressão Gênica/fisiologia , Metaloendopeptidases/metabolismo , Sistema Nervoso , Fatores Etários , Animais , Animais Recém-Nascidos , Embrião de Mamíferos , Feminino , Hibridização In Situ/métodos , Masculino , Metaloendopeptidases/genética , Sistema Nervoso/embriologia , Sistema Nervoso/crescimento & desenvolvimento , Sistema Nervoso/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
16.
Gene Ther ; 13(16): 1244-50, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16625241

RESUMO

We designed a new promoter that drives transgene expression in an exclusively neuron-specific manner. The promoter of superior cervical ganglion10 (SCG10), expressed in neurons, was further modified to enhance its neuron specificity and activity by changing its length and fusing a multiple neuronal restrictive silencer element (NRSE) to its upstream or downstream regions. The promoter, which contained 2 kb original promoter length and two extra NRSEs in its downstream region, eventually exhibited remarkable neuron specificity as well as strong activity. To further amplify the promoter activity, the promoter was introduced into a Cre recombinase (Cre)-expressing adenovirus, and subsequent combination with Cre-inducible enhanced green fluorescence protein (EGFP)-expressing adenovirus vector, which has much stronger general promoter, resulted in a remarkably strong gene expression exclusively in neuronal cells of mixed cultures and in an animal model. This system is also applicable to astrocyte-specific expression; for instance, by changing the Cre promoter cassette to an astrocyte-specific promoter. The present relatively compact promoter combined with Cre/loxP system could be useful for a wide range of transgene experiments in vivo as well as for clinical applications.


Assuntos
Encéfalo/metabolismo , Terapia Genética/métodos , Integrases/genética , Proteínas de Membrana/genética , Neurônios/metabolismo , Regiões Promotoras Genéticas , Células 3T3 , Adenoviridae/genética , Animais , Astrócitos/metabolismo , Técnicas de Cocultura , Elementos Facilitadores Genéticos , Amplificação de Genes , Engenharia Genética , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Humanos , Camundongos , Microscopia de Fluorescência , Ratos , Elementos Silenciadores Transcricionais/genética , Estatmina , Transdução Genética
17.
Kyobu Geka ; 57(13): 1177-84, 2004 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-15609653

RESUMO

213 patients who underwent surgical treatment for the valvular disease through partial sternotomy were studied. We started the minimally invasive valvular surgery in July 1997. All the valvular diseases were indicated for the minimally invasive surgery except for the annulo-aortic ectasia and the concomitant disease with coronary artery bypass surgery. Ascending aorta was selected as an arterial cannulation place if we could choice it through intraoperative echocardiography. Venous cannulae 22-24 Fr were inserted into the venae cavae directly or through right atrium. Negative pressure venous drainage (maximally 90 mmHg) was performed if necessarily. We did single approach as possible. Mortality rate was 3.8%. We could complete 96.2% of our series as a minimally invasive surgery. Post operative intensive care unit (ICU) stay and hospital stay through partial sternotomy were significantly shorter than those through full sternotomy.


Assuntos
Valva Aórtica/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Valva Mitral/cirurgia , Esterno/cirurgia , Toracotomia/métodos , Idoso , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Taxa de Sobrevida , Toracotomia/mortalidade
18.
Neuroscience ; 113(2): 387-94, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12127095

RESUMO

In the rat pineal gland, prominent expression of serine protease inhibitor 3 (SPI-3) mRNA is seen after systemic injection of lipopolysaccharide. The up-regulation of SPI-3 mRNA expression is also confirmed by northern blotting. Most SPI-3 mRNA-positive cells simultaneously express synaptophysin, a marker for pinealocytes, but not glial fibrillary acidic protein, a marker for astrocytes. This indicates that SPI-3 mRNA-positive cells are pinealocytes. Almost all SPI-3 mRNA-positive cells also showed translocation of the signal transducers and activators of transcription 3 (STAT3) into nuclei after lipopolysaccharide injection. These data support previous in vitro results that SPI-3 expression is induced in a STAT3-mediated manner. In addition, the expression of ciliary neurotrophic factor receptor (CNTFR) and leukemia inhibitory factor receptor (LIFR) mRNAs, but not of interleukin 6 receptor mRNA, was up-regulated after systemic lipopolysaccharide treatment. Because these receptors are upstream of STAT3, the present results suggest that cytokines such as LIF and/or CNTF induce SPI-3 expression via STAT3 in the pineal gland in response to inflammatory stimulus. We conclude that although the functional consequences of SPI-3 in the pineal gland during systemic inflammation are unknown, SPI-3 may have a crucial role in preventing some degenerative proteolysis induced by inflammatory stimuli.


Assuntos
Proteínas de Fase Aguda/metabolismo , Inflamação/metabolismo , Glândula Pineal/metabolismo , Proteínas de Fase Aguda/genética , Animais , Proteínas de Ligação a DNA/metabolismo , Imuno-Histoquímica , Subunidade alfa de Receptor de Fator Inibidor de Leucemia , Lipopolissacarídeos/farmacologia , Masculino , Glândula Pineal/citologia , Glândula Pineal/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptor do Fator Neutrófico Ciliar/genética , Receptores de Citocinas/genética , Receptores de OSM-LIF , Fator de Transcrição STAT3 , Serpinas , Transativadores/metabolismo
19.
J Submicrosc Cytol Pathol ; 34(4): 367-76, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12575835

RESUMO

This study was aimed to demonstrate the regeneration of skeletal muscle fibers in the stroma reaction during tumor invasion, using the rat model of tongue carcinoma. By oral administration of 4-nitroquinoline N-oxide, squamous cell carcinoma (SCC) appeared in the epithelium, and deeply invaded the muscular layer, inducing the stroma reaction around the tumor. Regenerating muscle fibers, characterized by the immature profiles of sparse myofibrils, centrally disposed multi-nuclei, and abundant mitochondria, were extended from the surrounding normal muscles into the stroma. By immunohistochemistry, some of them expressed BF-45, a marker for an early stage of myodifferentiation, similar to the regenerating muscle fibers in the bupivacaine hydrochloride-induced injury. They were closely associated with the stromal components such as ED-1-positive macrophages, alpha-smooth muscle actin-positive myofibroblasts, and factor VIII-related antigen-positive vascular endothelial cells, suggesting the roles of their interactions in muscle regeneration. Immature muscle fibers were usually devoid of acetylcholinesterase-positive endplates on them, but some were reinnervated by the terminal axons. The present results indicate that skeletal muscle regeneration is induced in association with the stroma reaction during SCC invasion in the tongue.


Assuntos
Carcinoma de Células Escamosas/fisiopatologia , Músculo Esquelético/fisiologia , Invasividade Neoplásica/fisiopatologia , Regeneração/fisiologia , Neoplasias da Língua/fisiopatologia , 4-Nitroquinolina-1-Óxido/toxicidade , Acetilcolinesterase/análise , Animais , Biomarcadores Tumorais , Bupivacaína/toxicidade , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Modelos Animais de Doenças , Feminino , Técnicas Imunoenzimáticas , Microscopia Eletrônica , Músculo Esquelético/química , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Miofibrilas/efeitos dos fármacos , Miofibrilas/fisiologia , Miofibrilas/ultraestrutura , Ratos , Ratos Wistar , Organismos Livres de Patógenos Específicos , Células Estromais/ultraestrutura , Succinato Desidrogenase/análise , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/patologia
20.
Invest Ophthalmol Vis Sci ; 42(11): 2427-33, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11581179

RESUMO

PURPOSE: To ascribe the serine protease inhibitor 3 (SPI-3) as an ocular acute inflammatory molecule and to clarify its producing cells in an endotoxin-induced uveitis (EIU) model. METHODS: Male Wistar rats were injected with lipopolysaccharide (LPS), and the expression of SPI-3 mRNA in the ocular tissues was examined by in situ hybridization (ISH) and Northern blot analysis. A combination of ISH and immunohistochemistry (IHC) were performed to prove the colocalization of SPI-3 mRNA and either glial fibrillary acidic protein (GFAP) or OX-42. The expression of phosphorylated STAT3 (pSTAT3) was demonstrated by IHC and Western blot after LPS injection. The colocalization of SPI-3 mRNA and pSTAT3 was finally examined by the double labeling of ISH and IHC. RESULTS: After LPS injection, the expression of SPI-3 mRNA in ocular tissues was quickly upregulated and reached a peak between 12 and 24 hours after injection. An intense mRNA signal was observed in epithelial cells of the iris and ciliary body and the innermost retinal layer. In the retina, SPI-3 mRNA was colocalized with GFAP, demonstrating that the cells expressing SPI-3 mRNA were astrocytes. After LPS treatment, SPI-3 mRNA and pSTAT3 were colocalized in retinal astrocytes, and pSTAT3 expression appeared slightly earlier than that of SPI-3 mRNA. CONCLUSIONS: Ocular inflammation induced the transient expression of SPI-3 mRNA in retinal astrocytes and epithelial cells in the iris and ciliary body, particularly during early phase of the inflammation. Simultaneously, the activation of STAT3 (phosphorylation of STAT3) occurred slightly earlier in astrocytes. This supports the previous in vitro results that SPI-3 expression is induced in a STAT3-mediated manner. SPI-3 may have some crucial roles in preventing some degenerative proteolysis, which is induced by inflammatory stimuli.


Assuntos
Proteínas de Fase Aguda/genética , Antígenos CD , Antígenos de Neoplasias , Antígenos de Superfície , Proteínas Aviárias , Proteínas Sanguíneas , Olho/enzimologia , Lipopolissacarídeos , Salmonella typhimurium , Inibidores de Serina Proteinase/genética , Uveíte/enzimologia , Proteínas de Fase Aguda/biossíntese , Proteínas de Fase Aguda/metabolismo , Animais , Astrócitos/enzimologia , Basigina , Northern Blotting , Corpo Ciliar/enzimologia , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/enzimologia , Olho/patologia , Proteínas do Olho/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Técnicas Imunoenzimáticas , Hibridização In Situ , Iris/enzimologia , Masculino , Glicoproteínas de Membrana/metabolismo , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Retina/enzimologia , Fator de Transcrição STAT3 , Inibidores de Serina Proteinase/biossíntese , Serpinas , Transativadores/metabolismo , Uveíte/patologia
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